Merge pull request #15 from erindesu/master

Fixed some incompatible old code

src/lexer.rs

@@ -88,9 +88,6 @@ pub enum Token {
     #[token("if")]
     If,
 
-    #[token("else")]
-    Else,
-
     #[token("loop")]
     Loop,
 

src/parser/item.rs

@@ -53,7 +53,7 @@ impl From<Iden> for Expr {
 pub enum Stmt {
     VariableDeclaration {
         iden: Iden,
-        init: Option<Box<Item>>,
+        init: Option<Expr>,
     },
     FunctionDeclaration {
         iden: Iden,
@@ -65,7 +65,7 @@ pub enum Stmt {
         body: String,
     },
     If {
-        cond: Box<Item>,
+        cond: Expr,
         body: Vec<Item>,
     },
     FunctionCall {
@@ -75,6 +75,11 @@ pub enum Stmt {
     Loop {
         body: Vec<Item>,
     },
+
+    VarAssignment {
+        iden: Iden,
+        value: Expr,
+    },
     Break,
     HopBack,
     Print(Expr),

src/parser/mod.rs

@@ -69,6 +69,7 @@ impl<'a> Parser<'a> {
             | Token::String(_)
             | Token::Nul
             | Token::LeftParenthesis
+            | Token::Assignment
             | Token::LogNot => self.parse_ops(token),
 
             // Control flow
@@ -98,7 +99,7 @@ impl<'a> Parser<'a> {
             }
 
             _ => Err(Error {
-                kind: ErrorKind::SyntaxError("Unexpected identifier".to_owned()),
+                kind: ErrorKind::SyntaxError("Unexpected token".to_owned()),
                 position: start..self.lexer.span().end,
             }),
         }
@@ -110,13 +111,31 @@ impl<'a> Parser<'a> {
     fn variable_declaration(&mut self) -> ParseResult {
         let iden = self.require_iden()?;
 
-        let init = match self.lexer.next() {
+        let peek = self.lexer.peek().clone();
-            Some(Token::Semicolon) => None,
+        let init = match peek {
+            Some(Token::Semicolon) => {
+                self.lexer.next();
+                None
+            }
             Some(Token::Assignment) => {
-                let value = self.lexer.next();
+                self.lexer.next();
-                let value = self.parse_item(value)?;
+                let next = self.lexer.next();
-                self.require(Token::Semicolon)?;
+                let mut value = self.parse_expr(next)?;
-                Some(Box::new(value))
+                loop {
+                    let peek = self.lexer.peek().clone();
+                    value = match peek {
+                        Some(Token::Semicolon) => break,
+                        None => {
+                            return Err(Error {
+                                kind: ErrorKind::EndOfTokenStream,
+                                position: self.lexer.span(),
+                            })
+                        }
+                        Some(t) => self.parse_operation(Some(t), value)?,
+                    };
+                }
+                self.lexer.next();
+                Some(value)
             }
             _ => {
                 return Err(Error {
@@ -134,6 +153,7 @@ impl<'a> Parser<'a> {
     /// `functio [iden] ([expr], [expr]) { ... }
     fn function_declaration(&mut self) -> ParseResult {
         let iden = self.require_iden()?;
+
         self.require(Token::LeftParenthesis)?;
         let mut args = vec![];
         loop {
@@ -144,7 +164,9 @@ impl<'a> Parser<'a> {
                 _ => return Err(self.unexpected_token(None)),
             }
         }
+
         self.require(Token::LeftBrace)?;
+
         // Parse function body
         let body = self.parse_body()?;
 
@@ -191,19 +213,12 @@ impl<'a> Parser<'a> {
     /// Parse If-stmt
     pub fn if_cond(&mut self) -> ParseResult {
         self.require(Token::LeftParenthesis)?;
-        let cond = self.lexer.next();
+        let cond = self.parse_paren()?;
-        let cond = self.parse_item(cond)?;
-        self.require(Token::RightParenthesis)?;
-
         self.require(Token::LeftBrace)?;
 
         let body = self.parse_body()?;
 
-        Ok(Stmt::If {
+        Ok(Stmt::If { cond, body }.into())
-            cond: Box::new(cond),
-            body,
-        }
-        .into())
     }
 
     /// Parse loop
@@ -256,23 +271,17 @@ mod tests {
             body: vec![
                 VariableDeclaration {
                     iden: Iden("a".to_owned()),
-                    init: Some(Box::new(
+                    init: Some(Add {
-                        Add {
+                        left: Box::new(Literal(Value::Int(3))),
-                            left: Box::new(Literal(Value::Int(3))),
+                        right: Box::new(Literal(Value::Int(2))),
-                            right: Box::new(Literal(Value::Int(2))),
+                    }),
-                        }
-                        .into(),
-                    )),
                 }
                 .into(),
                 If {
-                    cond: Box::new(
+                    cond: Eq {
-                        Eq {
+                        left: Box::new(Iden("a".to_owned()).into()),
-                            left: Box::new(Iden("a".to_owned()).into()),
+                        right: Box::new(Literal(Value::Int(5)).into()),
-                            right: Box::new(Literal(Value::Int(5)).into()),
+                    },
-                        }
-                        .into(),
-                    ),
                     body: vec![Break.into()],
                 }
                 .into(),
@@ -289,7 +298,7 @@ mod tests {
         let expected: &[Item] = &[
             VariableDeclaration {
                 iden: Iden("script".to_owned()),
-                init: Some(Box::new(Literal(Value::Nul).into())),
+                init: Some(Literal(Value::Nul)),
             }
             .into(),
             Print(Iden("script".to_owned()).into()).into(),

src/parser/ops.rs

@@ -20,34 +20,87 @@ macro_rules! gen_infix {
 
 impl<'a> Parser<'a> {
     pub(super) fn parse_ops(&mut self, token: Token) -> ParseResult {
-        if matches!(self.lexer.peek(), Some(Token::LeftParenthesis)) {
+        // Statements
-            return self.fn_call(token);
+        match self.lexer.peek() {
+            Some(Token::LeftParenthesis) => return self.fn_call(token),
+            Some(Token::Assignment) => return self.parse_assignment(token),
+            _ => (),
         }
 
         let mut buf: Expr = self.parse_expr(Some(token))?;
 
         loop {
-            buf = match self.lexer.peek() {
+            let peek = self.lexer.peek().clone();
-                Some(Token::Addition) => self.addition(buf)?,
+            buf = match peek {
-                Some(Token::Subtract) => self.subtract(buf)?,
+                // Print statement
-                Some(Token::Multiply) => self.multiply(buf)?,
-                Some(Token::Divide) => self.divide(buf)?,
-                Some(Token::OpLt) => self.cmplt(buf)?,
-                Some(Token::OpGt) => self.cmpgt(buf)?,
-                Some(Token::OpEq) => self.cmpeq(buf)?,
-                Some(Token::OpNeq) => self.cmpneq(buf)?,
-                Some(Token::LogAnd) => self.logand(buf)?,
-                Some(Token::LogOr) => self.logor(buf)?,
                 Some(Token::Print) => {
                     self.lexer.next();
                     self.require(Token::Semicolon)?;
                     return Ok(Stmt::Print(buf).into());
                 }
-                _ => return Ok(buf.into()),
+                None => return Ok(buf.into()),
+
+                // An expression
+                _ => self.parse_operation(peek, buf)?,
             }
         }
     }
 
+    /// Match and perform
+    pub(super) fn parse_operation(&mut self, token: Option<Token>, buf: Expr) -> ExprResult {
+        match token {
+            Some(Token::Addition) => self.addition(buf),
+            Some(Token::Subtract) => self.subtract(buf),
+            Some(Token::Multiply) => self.multiply(buf),
+            Some(Token::Divide) => self.divide(buf),
+            Some(Token::OpLt) => self.cmplt(buf),
+            Some(Token::OpGt) => self.cmpgt(buf),
+            Some(Token::OpEq) => self.cmpeq(buf),
+            Some(Token::OpNeq) => self.cmpneq(buf),
+            Some(Token::LogAnd) => self.logand(buf),
+            Some(Token::LogOr) => self.logor(buf),
+            Some(Token::LeftParenthesis) => Err(Error {
+                kind: ErrorKind::SyntaxError("Function call isn't an expression!".to_owned()),
+                position: self.lexer.span(),
+            }),
+            Some(_) | None => Err(self.unexpected_token(None)),
+        }
+    }
+
+    fn parse_assignment(&mut self, token: Token) -> ParseResult {
+        self.lexer.next();
+
+        // Extract identifier
+        let iden = if let Token::Identifier(i) = token {
+            Iden(i)
+        } else {
+            return Err(Error {
+                kind: ErrorKind::InvalidIdentifier,
+                position: self.lexer.span(),
+            });
+        };
+
+        let next = self.lexer.next();
+        let mut value = self.parse_expr(next)?;
+
+        loop {
+            let peek = self.lexer.peek().clone();
+            value = match peek {
+                Some(Token::Semicolon) => break,
+                None => {
+                    return Err(Error {
+                        kind: ErrorKind::EndOfTokenStream,
+                        position: self.lexer.span(),
+                    })
+                }
+                Some(t) => self.parse_operation(Some(t), value)?,
+            };
+        }
+
+        self.lexer.next();
+
+        Ok(Stmt::VarAssignment { iden, value }.into())
+    }
     // Generate infix
     gen_infix! {
         addition => Add;
@@ -94,33 +147,18 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse parenthesieted expression
-    fn parse_paren(&mut self) -> ExprResult {
+    pub(super) fn parse_paren(&mut self) -> ExprResult {
         let next = self.lexer.next();
         let mut buf = self.parse_expr(next)?;
         loop {
-            let next = self.lexer.peek().clone().ok_or(Error {
+            let peek = self.lexer.peek().clone();
-                kind: ErrorKind::EndOfTokenStream,
+            buf = match peek {
-                position: self.lexer.span(),
-            })?;
-
-            buf = match Some(next) {
-                Some(Token::Addition) => self.addition(buf)?,
-                Some(Token::Subtract) => self.subtract(buf)?,
-                Some(Token::Multiply) => self.multiply(buf)?,
-                Some(Token::Divide) => self.divide(buf)?,
-                Some(Token::LeftParenthesis) => {
-                    return Err(Error {
-                        kind: ErrorKind::SyntaxError(
-                            "Function call isn't an expression!".to_owned(),
-                        ),
-                        position: self.lexer.span(),
-                    })
-                }
                 Some(Token::RightParenthesis) => {
                     self.lexer.next();
                     return Ok(buf);
                 }
-                _ => return Ok(buf),
+                None => return Ok(buf),
+                Some(t) => self.parse_operation(Some(t), buf)?,
             };
         }
     }